Free online AUP3 to AAC converter

Audacity project files must be rendered before they can be used by phones, media players, or editors that accept AAC. Exporting the project creates a playable AAC stream, usually stored in an .m4a container.

What the AUP3 format is

.aup3 is Audacity’s project format, created by Audacity 3.0 and later. It is a SQLite-based project database containing imported or recorded audio, track arrangement, labels, clips, volume changes, and edit information; it is not a conventional audio file that most players can open.

You normally encounter an AUP3 file after recording or editing in Audacity. The project must be opened in Audacity, or rendered by a compatible conversion system, because a generic audio converter cannot reliably interpret its project structure.

What the AAC format is

AAC is a lossy audio codec designed to provide smaller files than uncompressed PCM audio at comparable perceived quality. It is widely supported by smartphones, browsers, streaming systems, media players, and video editors.

AAC audio is commonly delivered in an MPEG-4 container with the .m4a extension. A raw AAC elementary stream may use .aac, but .m4a is usually the more compatible choice for exported music, speech, and podcasts.

How to convert AUP3 to AAC

Using Audacity

1. Install or open Audacity 3.x and open the .aup3 project with File → Open.
2. Check the track mute, solo, volume, pan, sample-rate, and selection settings. Audacity exports the audible result of these settings, not the editable project structure.
3. Choose File → Export Audio, select M4A (AAC) or an equivalent AAC/MPEG-4 option if it is available, and choose the destination filename.
4. Select the required bitrate or quality setting, then export. Stereo music commonly uses 192–256 kbps; speech often needs less, such as 64–96 kbps.

If Audacity does not show an M4A or AAC export option, install and enable the FFmpeg library supported by your Audacity version, then reopen the export dialog. Menu names and available AAC options vary between Audacity releases and operating systems.

Using an intermediate WAV and FFmpeg

When direct AAC export is unavailable, first use File → Export Audio in Audacity and save a PCM WAV file. Then run:

ffmpeg -i input.wav -c:a aac -b:a 192k output.m4a

Replace input.wav with the exported WAV filename and adjust -b:a to the desired bitrate. For a raw AAC file rather than an M4A file, use an .aac output name, although M4A normally has better application compatibility.

You can also convert the file on the 101convert.com website for free without installing software, if its AUP3 conversion workflow supports the project and export settings you need.

Quality and compatibility limits

AAC encoding is lossy: exporting cannot restore detail already removed from the source, and repeated lossy conversions can reduce quality. Export from the original Audacity project rather than from an existing compressed file, and use a higher bitrate when preserving music quality matters.

The exported file contains a rendered mix, not separate editable Audacity tracks, clips, labels, or effect parameters. Keep the original .aup3 project for future editing. If the project uses third-party plug-ins or missing media references, render it in Audacity first and verify the resulting AAC file for missing effects or silent tracks.